This invention relates generally to means and methods for forming holes in workpieces and relates more particularly to means and methods for forming holes in webbing comprised of thermoplastic material.
Webbing comprised of synthetic thermoplastic materials such as Nylon.RTM., polyester or polypropylene, is commonly used in the fabrication of straps for pet collars, horse halters, military slings and luggage straps. Each of such straps commonly includes a series of holes along its length and utilizes a fastener which may be passed through any one of the holes to, for example, accommodate an adjustment in the length of the strap or secure the strap in a desired position.
To form a hole in webbing comprised of thermoplastic material, it is known that a metal spike may be heated and then forced through the webbing in what is believed to be a combination melting and punching action. Typically, the material melted by the heated spike is forced radially outwardly where the material accumulates as melt build-up or flash adjacent the edge of the hole. However, hole-forming methods involving such techniques are likely to result in holes having edges which are susceptible to cracking and are not always satisfactory from an appearance standpoint. Furthermore, if a grommet or eyelet is desired to be installed through the formed holes, the material which has accumulated adjacent the edges of the holes may render installation of the grommets or eyelets difficult.
Accordingly, it is an object of the present invention to provide a new and improved apparatus and method for forming holes in webbing comprised of thermoplastic material.
Another object of the present invention is to provide such an apparatus and method for forming holes having edges which are not susceptible to cracking and are aesthetically appealing.
Still another object of the present invention is to provide such an apparatus and method for forming holes in thermoplastic webbing through which grommets or eyelets may be easily installed.
A further object of the present invention is to provide such an apparatus which is uncomplicated in construction and effective in operation.